The retractable skylight at the World Trade Center Oculus will reopen on 9/11

The skylight at the World Trade Center Oculus will reopen on September 11 at exactly 10:28 a.m., the same time the North Tower fell in 2001. The “Way of Light,” which happens every year on 9/11, will shine through the opening, bringing light to the bustling WTC transit center below. Santiago Calatrava designed the Oculus oriented in a way that allows sunlight to cross the floor, directly along the axis of the building.

According to a spokesperson for the building, the “Way of Light,” or the path of light that travels through the skylight, represents “the light that continues to shine through after the darkness of the tragedy.”

Originally, Calatrava’s design called for the two sides of the hub to open up to 50 feet, simulating a bird’s flapping wings. But as the cost of construction continued to increase, the moving roof was dropped from the project, as the New York Times reported in 2015.

The Times reported the skylight uses 224 pieces of glass in 40 panels, which are cantilevered from the steel structure. At its highest point, the skylight measures 160 feet above the ground.